1. Field of the Invention
This invention relates generally to a transport and storage container for liquids and more particularly to a secondary containment for transporting and storing Diesel Exhaust Fluid (DEF).
2. Brief Description of Prior Art
In 1990, Congress passed and President George H.W. Bush signed amendments to the Clean Air Act that directed the U.S. Environmental Protection Agency (EPA) to regulate air pollutants from a variety of industrial and commercial sources including motor vehicles.
Among the air pollutants EPA regulates under the authority of the Clean Air Act are particulate matter (PM) and Nitrogen Oxides (NOx) by products of diesel exhausts that are precursors to smog. PM has been linked to higher incidences of childhood asthma, among other health hazards. The more sulfur motor fuel contains, the more PM it produces when burned. NOx is produced during the process of high-temperature combustion such as is present in a motor vehicle engine, and can react with sunlight along with volatile organic compounds to form smog.
Exhaust treatment systems work hand in hand with reductions in the amount of sulfur in diesel fuel to reduce PM and NOx. In order to meet EPA regulations on limiting emissions of PM and NOx from their vehicle exhaust system many of the engine manufactures have or will adopt a pre-exhaust treatment system such as Selective Catalytic Reduction (SCR). SCR engines require a steady flow of Diesel Exhaust Fluid (DEF)—comprised of a solution of urea and water- to convert engine emissions into harmless levels of nitrogen and water vapor. As such, DEF will be required in most diesel vehicles in order to replenish the clean exhaust systems using SCR.
The term “diesel exhaust fluid” (DEF) only recently entered the United States fleet industry with the advent of a particular type of clean exhaust system, SCR. Because these clean exhaust systems are sensitive and the material must remain pure, quality is a key concern for anyone marketing or handling DEF. In this regard, distribution network certification systems are being established to meet the need for quality DEF through truck stops and retail outlets and to accommodate a wide variety of dispensing options.
DEF is not an additive, and is not mixed with diesel fuel. In a vehicle outfitted with an SCR system, DEF has a separate on-board tank (6-10 gallons on light-duty vehicles; 10-30 gallons on heavy-duty vehicles). From its storage tank, DEF is pumped through a filter and injector and then, into the exhaust system. In the after treatment system, the heat from the exhaust hydrolyzes the urea into two components: Anhydrous Ammonia and CO2. The gas mixture of ammonia and NOx passes across the catalyst and reduces them to elemental nitrogen and water, harmless since air is composed of 78% elemental nitrogen. The additional CO2 emitted due to urea decomposition is offset by enhanced fuel economy. A gallon of diesel emits ten times more CO2 than a gallon of DEF.
DEF is distributed in the fleet marketplace through truck stops along interstate routes and through truck terminals. Fuel oil distributors generally vend DEF in mini-bulk storage containers that are delivered to a fuel island and hooked to a dispensing pump for retail at service locations.
As stated, the integrity of DEF through the supply chain is critical. Purity and concentration must be maintained through the dispensing equipment, storage and handling, including any small packaging for DEF. Supply-chain partners must undergo a rigorous process to handle the fluid properly. It can therefore be appreciated that there exists a continuing need for a transport and storage system for storing DEF in order to ensure proper DEF dispensing operability especially where extreme temperature conditions exist, and handling DEF for retail installation. It is also imperative that the transport and storage system maintain the purity and concentration to satisfy EPA standards. The present invention meets this need.